widgets-config.php

<?php
if ( ! function_exists( "RdxIO_add_widgets" ) ):
        function RdxIO_add_widgets( $widgets ) {

            $widgets[] = array(
                'id' => 'testWidget',
                'title' => 'Test Widget Title',
                'name' => 'WORK',
                'desc' => 'This is the description',
                'fields' => array(
                    array(
                        "id" => 'textTest',
                        'title' => 'Text Test',
                        'subtitle' => 'Text Test Subtitle',
                        'desc' => 'Text Test Description',
                        'type' => 'text'
                    ),
                )
            );

            return $widgets;
        }

        add_action( 'redux/widgets/rdxIO/widgets', 'RdxIO_add_widgets' );
    endif;